First GM TDH-5103 model was a property of GM Engineering and was later used as the pilot air-suspension job (TDH-5105-EXP 305). In 1953 it was painted by GM in San Francisco Municipal Railway 'wings' livery, numbered 5105 and sent to MUNI. At that time a ballot proposition was intended to provide money to buy new buses for San Francisco. GM was very interested as MUNI was the only big transit property in the country that had never purchased any GM buses. This coach operated in revenue service in September-December 1953 on lines 14, 15, 71 and 72. The bond issue failed and coach was returned to GM. In Summer 1956 it became one of two experimental air-conditioned transits. In August 1958 it was sold to New Orleans Public Service.